index.html

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Javascript Calculator - developermithu</title>
    <link rel="stylesheet" href="style.css" />
    <script src="app.js" defer></script>
  </head>
  <body>
    <div id="calculator">
      <input type="text" id="display" disabled />
      <br />
      <button id="ac" class="operator">AC</button>
      <button id="de" class="operator">DE</button>
      <button id="." class="operator">.</button>
      <button id="/" class="operator">/</button>
      <br />
      <button id="7">7</button>
      <button id="8">8</button>
      <button id="9">9</button>
      <button id="*" class="operator">*</button>
      <br />
      <button id="4">4</button>
      <button id="5">5</button>
      <button id="6">6</button>
      <button id="-" class="operator">-</button>
      <br />
      <button id="1">1</button>
      <button id="2">2</button>
      <button id="3">3</button>
      <button id="+" class="operator">+</button>
      <br />
 
      <button id="00">00</button>
      <button id="0">0</button>
      <button id="=" class="equal operator">=</button>
      <br />
    </div>

    <footer>
     Developed by 👉 <a href="https://developermithu.vercel.app" target="_blank">Developer Mithu</a>
    </footer>
  </body>
</html>